\qquad
\begin{tikzpicture}[scale=1,tdplot_main_coords]
\pgfmathsetmacro{\xrot}{70} 
\pgfmathsetmacro{\zrot}{100}
\tdplotsetmaincoords{\xrot}{\zrot}
\pgfmathsetmacro{\rvec}{1.4} 
\pgfmathsetmacro{\rvecp}{0.5} 
\pgfmathsetmacro{\thetavec}{20} 
\pgfmathsetmacro{\thetavecp}{40} 
\pgfmathsetmacro{\phivec}{100}
\pgfmathsetmacro{\alpha}{\thetavecp+\thetavec}
\pgfmathsetmacro{\tanalpha}{tan(\alpha)}
\pgfmathsetmacro{\cosalphainv}{1/cos(\alpha)}
\pgfmathsetmacro{\cosphi}{cos(\phivec)}
\pgfmathsetmacro{\costheta}{cos(\thetavec)}
\pgfmathsetmacro{\sintheta}{sin(\thetavec)}
\pgfmathsetmacro{\sinphi}{sin(\phivec)}
\coordinate (O) at (0,0,0);
\def\l{0.8}
\def\d{1.8}
\tdplotsetcoord{P}{\rvec}{\thetavec}{\phivec} 
\tdplotsetcoord{Q}{\rvec}{\thetavec}{\phivec-180}
\tdplotsetcoord{S}{\rvecp*\cosalphainv}{-\thetavec}{\phivec}
\tdplotsetcoord{T}{\rvecp}{\thetavecp}{\phivec}
\tdplotsetcoord{U}{\rvecp*\cosalphainv}{\thetavecp+\alpha}{\phivec}
\tdplotsetcoord{E}{2}{-\thetavec}{\phivec}

\draw[color=red] (O) -- (P)  node[near end,anchor=north]{}; 
\draw[color=red] (O) -- (Q)  node[near end,anchor=north]{};

%\draw[dashed] (0,0,0) -- (\rvec,0,0) node[anchor=north east]{};
\draw[] (0,0,0) -- (\d,0,0) node[anchor=north east]{$x'$};
%\draw[dashed] (0,0,0) -- (0,\rvec,0) node[anchor= west]{};
\draw[] (0,0,0) -- (0,\d,0) node[anchor= west]{$y'$};
\draw[] (0,0,0) -- (0,0,\d-0.1) node[anchor=west]{$z'$};

%\tdplotdrawarc[]{(O)}{\rvec}{\zrot-180}{\zrot}{anchor=north}{}
%\tdplotdrawarc[dashed]{(O)}{\rvec}{\zrot}{\zrot+180}{anchor=north}{}

\tdplotdrawarc[color=red]{(Pz)}{\rvec*\sintheta}{0}{360}{anchor=north}{}
%\tdplotdrawarc[]{(O)}{0.2}{0}{\phivec}{anchor=north}{$\varphi$}
\tdplotsetthetaplanecoords{\phivec}
%\tdplotdrawarc[tdplot_rotated_coords]{(0,0,0)}{0.2}{0}{\thetavec}{anchor=east}{$\theta$}
%\draw[dashed] (0,0,0) -- (\rvec*\cosphi,\rvec*\sinphi,0);
%\draw[tdplot_rotated_coords] (\rvec,0,0) arc (0:90:\rvec); 
\tdplotsetrotatedcoords{\phivec}{\thetavecp}{0}
\tdplotsetrotatedcoordsorigin{(O)}
%\draw[color=myblue,tdplot_rotated_coords,->] (0,0,0) -- (\l,0,0) node[anchor=north west]{$\vec{e}_{\theta}$};
%\draw[color=myblue,tdplot_rotated_coords,->] (0,0,0) -- (0,\l,0) node[anchor=west]{$\vec{e}_{\varphi}$};
\draw[color=myblue,tdplot_rotated_coords] (0,0,0)
-- (0,0,\d) node[anchor=south west]{$z$};
\draw[color=blue,tdplot_rotated_coords] (T)
circle (\rvecp*\tanalpha) node[anchor=south]{};
\draw[color=blue] (S) -- (O);
\draw[color=blue] (U) -- (O);
\node[red,tdplot_screen_coords] at (0.7,1.5,0){Space cone};
\node[blue,tdplot_screen_coords] at (1.2,0.3,0){Body cone};
\draw[color=myblue,-latex,thick] (S) -- (E) node[anchor=south]{$\omega$};
\draw[color=myblue,-latex,thick] (Pz) -- (0,0,1.9) node[anchor=south]{$\vec{L}$};

%\draw[tdplot_screen_coords] (O) circle (\rvec);
\end{tikzpicture}